University of Oulu

Kilpijärvi, J.; Halonen, N.; Juuti, J.; Hannu, J. Microfluidic Microwave Sensor for Detecting Saline in Biological Range. Sensors 2019, 19, 819.

Microfluidic microwave sensor for detecting saline in biological range

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Author: Kilpijärvi, Joni1; Halonen, Niina1; Juuti, Jari1;
Organizations: 1Microelectronics Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, P.O. Box 4500, FI-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 5.2 MB)
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Language: English
Published: Multidisciplinary Digital Publishing Institute, 2019
Publish Date: 2019-04-04


A device for measuring biological small volume liquid samples in real time is appealing. One way to achieve this is by using a microwave sensor based on reflection measurement. A prototype sensor was manufactured from low cost printed circuit board (PCB) combined with a microfluidic channel made of polymethylsiloxane (PDMS). Such a sensor was simulated, manufactured, and tested including a vacuum powered sample delivery system with robust fluidic ports. The sensor had a broad frequency band from 150 kHz to 6 GHz with three resonance frequencies applied in sensing. As a proof of concept, the sensor was able to detect a NaCl content of 125 to 155 mmol in water, which is the typical concentration in healthy human blood plasma.

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Series: Sensors
ISSN: 1424-8220
ISSN-E: 1424-8220
ISSN-L: 1424-8220
Volume: 19
Issue: 4
Article number: 819
DOI: 10.3390/s19040819
Type of Publication: A1 Journal article – refereed
Field of Science: 213 Electronic, automation and communications engineering, electronics
Copyright information: © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (